Tissue-specific pathway activities: A retrospective analysis in COVID-19 patients.

The ACE2 receptors essential for SARS-CoV-2 infections are expressed not only in the lung but also in many other tissues in the human body. To better understand the disease mechanisms and progression, it is essential to understand how the virus affects and alters molecular pathways in the different affected tissues. In this study, we mapped the proteomics data obtained from Nie X. et al. (2021) to the pathway models of the COVID-19 Disease Map project and WikiPathways. The differences in pathway activities between COVID-19 and non-COVID-19 patients were calculated using the Wilcoxon test. As a result, 46% (5,235) of the detected proteins were found to be present in at least one pathway. Only a few pathways were altered in multiple tissues. As an example, the Kinin-Kallikrein pathway, an important inflammation regulatory pathway, was found to be less active in the lung, spleen, testis, and thyroid. We can confirm previously reported changes in COVID-19 patients such as the change in cholesterol, linolenic acid, and arachidonic acid metabolism, complement, and coagulation pathways in most tissues. Of all the tissues, we found the thyroid to be the organ with the most changed pathways. In this tissue, lipid pathways, energy pathways, and many COVID-19 specific pathways such as RAS and bradykinin pathways, thrombosis, and anticoagulation have altered activities in COVID-19 patients. Concluding, our results highlight the systemic nature of COVID-19 and the effect on other tissues besides the lung.

Pinostrobin from plants and propolis against human coronavirus HCoV-OC43 by modulating host AHR/CYP1A1 pathway and lipid metabolism.

Coronaviruses, as enveloped positive-strand RNA viruses, manipulate host lipid compositions to enable robust viral replication. Temporal modulation of the host lipid metabolism is a potential novel strategy against coronaviruses. Here, the dihydroxyflavone pinostrobin (PSB) was identified through bioassay that inhibited the increment of human coronavirus OC43 (HCoV-OC43) in human ileocecal colorectal adenocarcinoma cells. Lipid metabolomic studies showed that PSB interfered with linoleic acid and arachidonic acid metabolism pathways. PSB significantly decreased the level of 12, 13- epoxyoctadecenoic (12, 13-EpOME) and increased the level of prostaglandin E2. Interestingly, exogenous supplement of 12, 13-EpOME in HCoV-OC43-infected cells significantly stimulated HCoV-OC43 virus replication. Transcriptomic analyses showed that PSB is a negative modulator of aryl hydrocarbon receptor (AHR)/cytochrome P450 (CYP) 1A1signaling pathway and its antiviral effects can be counteracted by supplement of FICZ, a well-known AHR agonist. Integrative analyses of metabolomic and transcriptomic indicated that PSB could affect linoleic acid and arachidonic acid metabolism axis through AHR/CYP1A1 pathway. These results highlight the importance of the AHR/CYP1A1 pathway and lipid metabolism in the anti-coronavirus activity of the bioflavonoid PSB.

Acetylcholine, Fatty Acids, and Lipid Mediators Are Linked to COVID-19 Severity.

Lipid and cholinergic mediators are inflammatory regulators, but their role in the immunopathology of COVID-19 is still unclear. Here, we used human blood and tracheal aspirate (TA) to investigate whether acetylcholine (Ach), fatty acids (FAs), and their derived lipid mediators (LMs) are associated with COVID-19 severity. First, we analyzed the perturbation profile induced by SARS-CoV-2 infection in the transcriptional profile of genes related to the ACh and FA/LM pathways. Blood and TA were used for metabolomic and lipidomic analyses and for quantification of leukocytes, cytokines, and ACh. Differential expression and coexpression gene network data revealed a unique transcriptional profile associated with ACh and FA/LM production, release, and cellular signaling. Transcriptomic data were corroborated by laboratory findings: SARS-CoV-2 infection increased plasma and TA levels of arachidonic acid, 5-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid, 11-hydroxy-5Z,8Z,12E,14Z-eicosatetraenoic acid, and ACh. TA samples also exhibited high levels of PGE2, thromboxane B2, 12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid, and 6-trans-leukotriene B4 Bioinformatics and experimental approaches demonstrated robust correlation between transcriptional profile in Ach and FA/LM pathways and parameters of severe COVID-19. As expected, the increased neutrophil-to-lymphocyte ratio, neutrophil counts, and cytokine levels (IL-6, IL-10, IL-1ß, and IL-8) correlated with worse clinical scores. Glucocorticoids protected severe and critical patients and correlated with reduced Ach levels in plasma and TA samples. We demonstrated that pulmonary and systemic hyperinflammation in severe COVID-19 are associated with high levels of Ach and FA/LM. Glucocorticoids favored the survival of patients with severe/critical disease, and this effect was associated with a reduction in ACh levels.

Cytochrome P450-derived fatty acid epoxides and diols in angiogenesis and stem cell biology.

Cytochrome P450 (CYP) enzymes are frequently referred to as the third pathway for the metabolism of arachidonic acid. While it is true that these enzymes generate arachidonic acid epoxides i.e. the epoxyeicosatrienoic acids (EETs), they are able to accept a wealth of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) to generate a large range of regio- and stereo-isomers with distinct biochemical properties and physiological actions. Probably the best studied are the EETs which have well documented effects on vascular reactivity and angiogenesis. CYP enzymes can also participate in crosstalk with other PUFA pathways and metabolize prostaglandin G2 and H2, which are the precursors of effector prostaglandins, to affect macrophage function and lymphangiogenesis. The activity of the PUFA epoxides is thought to be kept in check by the activity of epoxide hydrolases. However, rather than being inactive, the diols generated have been shown to regulate neutrophil activation, stem and progenitor cell proliferation and Notch signaling in addition to acting as exercise-induced lipokines. Excessive production of PUFA diols has also been implicated in pathologies such as severe respiratory distress syndromes, including COVID-19, and diabetic retinopathy. This review highlights some of the recent findings related to this pathway that affect angiogenesis and stem cell biology.

Potential inhibitors of the main protease of SARS-CoV-2 and modulators of arachidonic acid pathway: Non-steroidal anti-inflammatory drugs against COVID-19.

The main protease of SARS-CoV-2 is one of the key targets to develop and design antiviral drugs. There is no general agreement on the use of non-steroidal anti-inflammatory drugs (NSAIDs) in COVID-19. In this study, we investigated NSAIDs as potential inhibitors for chymotrypsin-like protease (3CLpro) and the main protease of the SARS-CoV-2 to find out the best candidates, which can act as potent inhibitors against the main protease. We also predicted the effect of NSAIDs on the arachidonic pathway and evaluated the hepatotoxicity of the compounds using systems biology techniques. Molecular docking was conducted via AutoDock Vina to estimate the interactions and binding affinities between selected NSAIDs and the main protease. Molecular docking results showed the presence of 10 NSAIDs based on lower binding energy (kcal/mol) toward the 3CLpro inhibition site compared to the co-crystal native ligand Inhibitor N3 (-6.6 kcal/mol). To validate the docking results, molecular dynamic (MD) simulations on the top inhibitor, Talniflumate, were performed. To obtain differentially-expressed genes under the 27 NSAIDs perturbations, we utilized the L1000 final Z-scores from the NCBI GEO repository (GSE92742). The obtained dataset included gene expression profiling signatures for 27 NSAIDs. The hepatotoxicity of NSAIDs was studied by systems biology modeling of Disturbed Metabolic Pathways. This study highlights the new application of NSAIDs as anti-viral drugs used against COVID-19. NSAIDs may also attenuate the cytokine storm through the downregulation of inflammatory mediators in the arachidonic acid pathway.

The role of 5-lipoxygenase in the pathophysiology of COVID-19 and its therapeutic implications.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, known as coronavirus disease 2019 (COVID-19) causes cytokine release syndrome (CRS), leading to acute respiratory distress syndrome (ARDS), acute kidney and cardiac injury, liver dysfunction, and multiorgan failure. Although several studies have discussed the role of 5-lipoxygenase (5-LOX) in viral infections, such as influenzae and SARS, it remains unexplored in the pathophysiology of COVID-19. 5-LOX acts on free arachidonic acid (AA) to form proinflammatory leukotrienes (LTs). Of note, numerous cells involved with COVID-19 (e.g., inflammatory and smooth muscle cells, platelets, and vascular endothelium) widely express leukotriene receptors. Moreover, 5-LOX metabolites induce the release of cytokines (e.g., tumour necrosis factor-α [TNF-α], interleukin-1α [IL-1α], and interleukin-1ß [IL-1ß]) and express tissue factor on cell membranes and activate plasmin. Since macrophages, monocytes, neutrophils, and eosinophils can express lipoxygenases, activation of 5-LOX and the subsequent release of LTs may contribute to the severity of COVID-19. This review sheds light on the potential implications of 5-LOX in SARS-CoV-2-mediated infection and the anticipated therapeutic role of 5-LOX inhibitors.

Large-Scale Plasma Analysis Revealed New Mechanisms and Molecules Associated with the Host Response to SARS-CoV-2.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to nearly every continent, registering over 1,250,000 deaths worldwide. The effects of SARS-CoV-2 on host targets remains largely limited, hampering our understanding of Coronavirus Disease 2019 (COVID-19) pathogenesis and the development of therapeutic strategies. The present study used a comprehensive untargeted metabolomic and lipidomic approach to capture the host response to SARS-CoV-2 infection. We found that several circulating lipids acted as potential biomarkers, such as phosphatidylcholine 14:0_22:6 (area under the curve (AUC) = 0.96), phosphatidylcholine 16:1_22:6 (AUC = 0.97), and phosphatidylethanolamine 18:1_20:4 (AUC = 0.94). Furthermore, triglycerides and free fatty acids, especially arachidonic acid (AUC = 0.99) and oleic acid (AUC = 0.98), were well correlated to the severity of the disease. An untargeted analysis of non-critical COVID-19 patients identified a strong alteration of lipids and a perturbation of phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, aminoacyl-tRNA degradation, arachidonic acid metabolism, and the tricarboxylic acid (TCA) cycle. The severity of the disease was characterized by the activation of gluconeogenesis and the metabolism of porphyrins, which play a crucial role in the progress of the infection. In addition, our study provided further evidence for considering phospholipase A2 (PLA2) activity as a potential key factor in the pathogenesis of COVID-19 and a possible therapeutic target. To date, the present study provides the largest untargeted metabolomics and lipidomics analysis of plasma from COVID-19 patients and control groups, identifying new mechanisms associated with the host response to COVID-19, potential plasma biomarkers, and therapeutic targets.

Bioactive Lipids in COVID-19-Further Evidence.

Previously, I suggested that arachidonic acid (AA, 20:4 n-6) and similar bioactive lipids (BALs) inactivate SARS-CoV-2 and thus, may be of benefit in the prevention and treatment of COVID-19. This proposal is supported by the observation that (i) macrophages and T cells (including NK cells, cytotoxic killer cells and other immunocytes) release AA and other BALs especially in the lungs to inactivate various microbes; (ii) pro-inflammatory metabolites prostaglandin E2 (PGE2) and leukotrienes (LTs) and anti-inflammatory lipoxin A4 (LXA4) derived from AA (similarly, resolvins, protectins and maresins derived from eicosapentaenoic acid: EPA and docosahexaenoic acid: DHA) facilitate the generation of M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages respectively; (iii) AA, PGE2, LXA4 and other BALs inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) synthesis; (iv) mesenchymal stem cells (MSCs) that are of benefit in COVID-19 elaborate LXA4 to bring about their beneficial actions and (v) subjects with insulin resistance, obesity, type 2 diabetes mellitus, hypertension, coronary heart disease and the elderly have significantly low plasma concentrations of AA and LXA4 that may render them more susceptible to SARS-CoV-2 infection and cytokine storm that is associated with increased mortality seen in COVID-19. Statins, colchicine, and corticosteroids that appear to be of benefit in COVID-19 can influence BALs metabolism. AA, and other BALs influence cell membrane fluidity and thus, regulate ACE-2 (angiotensin converting enzyme-2) receptors (the ligand through which SARS-CoV2 enters the cell) receptors. These observations lend support to the contention that administration of BALs especially, AA could be of significant benefit in prevention and management of COVI-19 and other enveloped viruses.

Can Bioactive Lipid Arachidonic Acid Prevent and Ameliorate COVID-19?

It is proposed that the bioactive lipid, arachidonic acid (AA, 20:4 n-6), can inactivate severe acute respiratory syndrome(SARS-CoV-2), facilitate M1 and M2 macrophage generation, suppress inflammation, prevent vascular endothelial cell damage, and regulate inflammation resolution processes based on the timely formation of prostaglandin E2 (PGE2) and lipoxin A4 (LXA4) based on the context. Thus, AA may be useful both to prevent and manage coronavrus disease-2019(COVID-19).

What about COVID-19 and arachidonic acid pathway?

BACKGROUND AND OBJECTIVE: COVID-19 is a highly contagious viral disease. In this study, we tried to define and discuss all the findings on the potential association between arachidonic acid (AA) pathway and COVID-19 pathophysiology. METHODS: A literature search across PubMed, Scopus, Embase, and Cochrane database was conducted. A total of 25 studies were identified. RESULTS: The data elucidated that COX-2 and prostaglandins (PGs), particularly PGE2, have pro-inflammatory action in COVID-19 pathophysiology. Arachidonic acid can act as endogenous antiviral compound. A deficiency in AA can make humans more susceptible to COVID-19. Targeting these pro-inflammatory mediators may help in decreasing the mortality and morbidity rate in COVID-19 patients. CONCLUSIONS: PGE2 levels and other PGs levels should be measured in patients with COVID-19. Lowering the PGE2 levels through inhibition of human microsomal prostaglandin E synthase-1 (mPGES-1) can enhance the host immune response against COVID-19. In addition, the hybrid compounds, such as COX-2 inhibitors/TP antagonists, can be an innovative treatment to control the overall balance between AA mediators in patients with COVID-19.

Is the anti-filarial drug diethylcarbamazine useful to treat COVID-19?

SARS-CoV-2 virus has resulted in a devastating pandemic of COVID-19. Exploring compounds that could offer a breakthrough in treatment is the need of the hour. Re-positioning cheap, freely available and safe drugs is a priority. The paper proposes evidence for the potential use of diethylcarbamazine (DEC) in the treatment of COVID-19. DEC has inhibitory effects on arachidonic acid metabolism to prostaglandins, little known anti-viral effects on animal retroviruses and demonstrated anti-inflammatory actions in animal models of lung inflammation indicating the need to explore this hypothesis further. We believe this is the first time DEC is being proposed to treat COVID-19.

[Study on treatment of "cytokine storm" by anti-2019-nCoV prescriptions based on arachidonic acid metabolic pathway].

Since the outbreak of 2019-nCoV, the epidemic has developed rapidly and the situation is grim. LANCET figured out that the 2019-nCoV is closely related to "cytokine storm". "Cytokine storm" is an excessive immune response of the body to external stimuli such as viruses and bacteria. As the virus attacking the body, it stimulates the secretion of a large number of inflammatory factors: interleukin(IL), interferon(IFN), C-X-C motif chemokine(CXCL) and so on, which lead to cytokine cascade reaction. With the exudation of inflammatory factors, cytokines increase abnormally in tissues and organs, interfering with the immune system, causing excessive immune response of the body, resulting in diffuse damage of lung cells, pulmonary fibrosis, and multiple organ damage, even death. Arachidonic acid(AA) metabolic pathway is principally used to synthesize inflammatory cytokines, such as monocyte chemotactic protein 1(MCP-1), tumor necrosis factor(TNF), IL, IFN, etc., which is closely related to the occurrence, development and regression of inflammation. Therefore, the inhibition of AA metabolism pathway is benefit for inhibiting the release of inflammatory factors in the body and alleviating the "cytokine storm". Based on the pharmacophore models of the targets on AA metabolic pathway, the traditional Chinese medicine database 2009(TCMD 2009) was screened. The potential herbs were ranked by the number of hit molecules, which were scored by pharmacophore fit value. In the end, we obtained the potential active prescriptions on "cytokine storm" according to the potential herbs in the "National novel coronavirus pneumonia diagnosis and treatment plan(trial version sixth)". The results showed that the hit components with the inhibitory effect on AA were magnolignan Ⅰ, lonicerin and physcion-8-O-ß-D-glucopy-ranoside, which mostly extracted from Magnoliae Officinalis Cortex, Zingiberis Rhizoma Recens, Lonicerae Japonicae Flos, Rhei Radix et Rhizoma, Salviae Miltiorrhizae Radix et Rhizoma, Scutellariae Radix, Gardeniae Fructus, Ginseng Radix et Rhizoma, Arctii Fructus, Dryopteridis Crassirhizomatis Rhizoma, Paeoniaeradix Rubra, Dioscoreae Rhizoma. Finally the anti-2019-nCoV prescriptions were analyzed to obtain the potential active prescriptions on AA metabolic pathway, Huoxiang Zhengqi Capsules, Jinhua Qinggan Granules, Lianhua Qingwen Capsules, Qingfei Paidu Decoction, Xuebijing Injection, Reduning Injection and Tanreqing Injection were found that may prevent 2019-nCoV via regulate cytokines. This study intends to provide reference for clinical use of traditional Chinese medicine to resist new coronavirus.